The Spreadtrum platform has 2 EIC controllers, one is in digital chip and
another one is in PMIC. The digital-chip EIC controller has 4 sub-modules:
debounce EIC, latch EIC, async EIC and sync EIC, each sub-module can has
multiple groups and each group contains 8 EICs. The PMIC EIC controller has
only one debounce EIC sub-module.

Each EIC can only be used as input mode, and has the capability to trigger
interrupts when detecting input signals.

Signed-off-by: Baolin Wang <baolin.w...@linaro.org>
---
 drivers/gpio/Kconfig         |    7 +
 drivers/gpio/Makefile        |    1 +
 drivers/gpio/gpio-eic-sprd.c |  782 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 790 insertions(+)
 create mode 100644 drivers/gpio/gpio-eic-sprd.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 184b581..2414391 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -159,6 +159,13 @@ config GPIO_DWAPB
          Say Y or M here to build support for the Synopsys DesignWare APB
          GPIO block.
 
+config GPIO_EIC_SPRD
+       tristate "Spreadtrum EIC support"
+       depends on ARCH_SPRD || COMPILE_TEST
+       select GPIOLIB_IRQCHIP
+       help
+         Say yes here to support Spreadtrum EIC device.
+
 config GPIO_EM
        tristate "Emma Mobile GPIO"
        depends on (ARCH_EMEV2 || COMPILE_TEST) && OF_GPIO
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 2e3d320..66eaa9e 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_GPIO_DA9055)     += gpio-da9055.o
 obj-$(CONFIG_GPIO_DAVINCI)     += gpio-davinci.o
 obj-$(CONFIG_GPIO_DLN2)                += gpio-dln2.o
 obj-$(CONFIG_GPIO_DWAPB)       += gpio-dwapb.o
+obj-$(CONFIG_GPIO_EIC_SPRD)    += gpio-eic-sprd.o
 obj-$(CONFIG_GPIO_EM)          += gpio-em.o
 obj-$(CONFIG_GPIO_EP93XX)      += gpio-ep93xx.o
 obj-$(CONFIG_GPIO_ETRAXFS)     += gpio-etraxfs.o
diff --git a/drivers/gpio/gpio-eic-sprd.c b/drivers/gpio/gpio-eic-sprd.c
new file mode 100644
index 0000000..ccc12a8
--- /dev/null
+++ b/drivers/gpio/gpio-eic-sprd.c
@@ -0,0 +1,782 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Spreadtrum Communications Inc.
+ * Copyright (c) 2018 Linaro Ltd.
+ */
+
+#include <linux/bitops.h>
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/spinlock.h>
+
+/* EIC registers definition */
+#define SPRD_EIC_DBNC_DATA             0x0
+#define SPRD_EIC_DBNC_DMSK             0x4
+#define SPRD_EIC_DBNC_IEV              0x14
+#define SPRD_EIC_DBNC_IE               0x18
+#define SPRD_EIC_DBNC_RIS              0x1c
+#define SPRD_EIC_DBNC_MIS              0x20
+#define SPRD_EIC_DBNC_IC               0x24
+#define SPRD_EIC_DBNC_TRIG             0x28
+#define SPRD_EIC_DBNC_CTRL0            0x40
+#define SPRD_EIC_DBNC_CTRL1            0x44
+#define SPRD_EIC_DBNC_CTRL2            0x48
+#define SPRD_EIC_DBNC_CTRL3            0x4c
+#define SPRD_EIC_DBNC_CTRL4            0x50
+#define SPRD_EIC_DBNC_CTRL5            0x54
+#define SPRD_EIC_DBNC_CTRL6            0x58
+#define SPRD_EIC_DBNC_CTRL7            0x5c
+
+#define SPRD_EIC_LATCH_INTEN           0x0
+#define SPRD_EIC_LATCH_INTRAW          0x4
+#define SPRD_EIC_LATCH_INTMSK          0x8
+#define SPRD_EIC_LATCH_INTCLR          0xc
+#define SPRD_EIC_LATCH_INTPOL          0x10
+#define SPRD_EIC_LATCH_INTMODE         0x14
+
+#define SPRD_EIC_ASYNC_INTIE           0x0
+#define SPRD_EIC_ASYNC_INTRAW          0x4
+#define SPRD_EIC_ASYNC_INTMSK          0x8
+#define SPRD_EIC_ASYNC_INTCLR          0xc
+#define SPRD_EIC_ASYNC_INTMODE         0x10
+#define SPRD_EIC_ASYNC_INTBOTH         0x14
+#define SPRD_EIC_ASYNC_INTPOL          0x18
+#define SPRD_EIC_ASYNC_DATA            0x1c
+
+#define SPRD_EIC_SYNC_INTIE            0x0
+#define SPRD_EIC_SYNC_INTRAW           0x4
+#define SPRD_EIC_SYNC_INTMSK           0x8
+#define SPRD_EIC_SYNC_INTCLR           0xc
+#define SPRD_EIC_SYNC_INTMODE          0x10
+#define SPRD_EIC_SYNC_INTBOTH          0x14
+#define SPRD_EIC_SYNC_INTPOL           0x18
+#define SPRD_EIC_SYNC_DATA             0x1c
+
+/*
+ * The digital-chip EIC controller can support maximum 3 groups, and each group
+ * contains 8 EICs.
+ */
+#define SPRD_EIC_MAX_GROUP             3
+#define SPRD_EIC_PER_GROUP_NR          8
+#define SPRD_EIC_DATA_MASK             GENMASK(7, 0)
+#define SPRD_EIC_BIT(x)                        ((x) & (SPRD_EIC_PER_GROUP_NR - 
1))
+
+/*
+ * The PMIC EIC controller only has one group, and each group now can contain
+ * 16 EICs.
+ */
+#define SPRD_PMIC_EIC_PER_GROUP_NR     16
+#define SPRD_PMIC_EIC_DATA_MASK                GENMASK(15, 0)
+#define SPRD_PMIC_EIC_BIT(x)           ((x) & (SPRD_PMIC_EIC_PER_GROUP_NR - 1))
+#define SPRD_PMIC_EIC_CACHE_NR_REGS    (SPRD_EIC_DBNC_TRIG + 0x4)
+
+#define SPRD_EIC_DBNC_MASK             GENMASK(11, 0)
+
+/*
+ * The Spreadtrum EIC (external interrupt controller) can only be used
+ * as input mode to generate interrupts if detecting input signals.
+ *
+ * The Spreadtrum platform has two EIC controllers, one EIC controller
+ * is in digital-chip, another one is in PMIC. There are some differences
+ * between this two EIC controllers. The digital-chip EIC controller
+ * includes 4 sub-modules: debounce EIC, latch EIC, async EIC and sync EIC,
+ * but the PMIC EIC controller only has one debounce EIC sub-module.
+ *
+ * The debounce EIC is used to capture input signal's stable status
+ * (ms grade) and a single-trigger mechanism is introduced into this
+ * sub-module to enhance the input event detection reliability. The
+ * debounce range is from 1ms to 4s with the step of 1ms.
+ *
+ * The latch EIC is used to latch some special input signal and send
+ * interrupts to MCU core.
+ *
+ * The async EIC uses 32k clock to capture short signal (us grade)
+ * to generate interrupt to MCU by level or edge trigger.
+ *
+ * The sync EIC is similar with GPIO's input function.
+ */
+enum sprd_eic_type {
+       SPRD_EIC_DEBOUNCE,
+       SPRD_EIC_LATCH,
+       SPRD_EIC_ASYNC,
+       SPRD_EIC_SYNC,
+       SPRD_EIC_PMIC_DEBOUNCE,
+       SPRD_EIC_MAX,
+};
+
+struct sprd_eic {
+       struct gpio_chip chip;
+       struct irq_chip intc;
+       void __iomem *base[SPRD_EIC_MAX_GROUP];
+       struct regmap *map;
+       u32 map_base;
+       u8 reg[SPRD_PMIC_EIC_CACHE_NR_REGS];
+       enum sprd_eic_type type;
+       spinlock_t lock;
+       struct mutex buslock;
+       int irq;
+};
+
+struct sprd_eic_data {
+       enum sprd_eic_type type;
+       u32 num_eics;
+};
+
+static const char *sprd_eic_label_name[SPRD_EIC_MAX] = {
+       "eic-debounce", "eic-latch", "eic-async",
+       "eic-sync", "eic-pmic-debounce",
+};
+
+static const struct sprd_eic_data sc9860_eic_dbnc_data = {
+       .type = SPRD_EIC_DEBOUNCE,
+       .num_eics = 8,
+};
+
+static const struct sprd_eic_data sc9860_eic_latch_data = {
+       .type = SPRD_EIC_LATCH,
+       .num_eics = 8,
+};
+
+static const struct sprd_eic_data sc9860_eic_async_data = {
+       .type = SPRD_EIC_ASYNC,
+       .num_eics = 8,
+};
+
+static const struct sprd_eic_data sc9860_eic_sync_data = {
+       .type = SPRD_EIC_SYNC,
+       .num_eics = 8,
+};
+
+static const struct sprd_eic_data pmic_eic_dbnc_data = {
+       .type = SPRD_EIC_PMIC_DEBOUNCE,
+       .num_eics = 16,
+};
+
+static inline void __iomem *sprd_eic_group_base(struct sprd_eic *sprd_eic,
+                                               unsigned int group)
+{
+       if (group >= SPRD_EIC_MAX_GROUP)
+               return NULL;
+
+       return sprd_eic->base[group];
+}
+
+static void sprd_eic_update(struct gpio_chip *chip, unsigned int offset,
+                           unsigned int reg, unsigned int val)
+{
+       struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
+       u32 shift;
+
+       if (sprd_eic->type == SPRD_EIC_PMIC_DEBOUNCE) {
+               shift = SPRD_PMIC_EIC_BIT(offset);
+
+               regmap_update_bits(sprd_eic->map, sprd_eic->map_base + reg,
+                                  BIT(shift), val << shift);
+       } else {
+               void __iomem *base = sprd_eic_group_base(sprd_eic,
+                                               offset / SPRD_EIC_PER_GROUP_NR);
+               unsigned long flags;
+               u32 orig, tmp;
+
+               shift = SPRD_EIC_BIT(offset);
+
+               spin_lock_irqsave(&sprd_eic->lock, flags);
+               orig = readl_relaxed(base + reg);
+
+               tmp = (orig & ~BIT(shift)) | (val << shift);
+               writel_relaxed(tmp, base + reg);
+               spin_unlock_irqrestore(&sprd_eic->lock, flags);
+       }
+}
+
+static int sprd_eic_read(struct gpio_chip *chip, unsigned int offset,
+                        unsigned int reg)
+{
+       struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
+       u32 shift;
+       u32 value;
+
+       if (sprd_eic->type == SPRD_EIC_PMIC_DEBOUNCE) {
+               int ret;
+
+               shift = SPRD_PMIC_EIC_BIT(offset);
+               ret = regmap_read(sprd_eic->map, sprd_eic->map_base + reg,
+                                 &value);
+               if (ret)
+                       return ret;
+
+               value &= SPRD_PMIC_EIC_DATA_MASK;
+       } else {
+               void __iomem *base = sprd_eic_group_base(sprd_eic,
+                                               offset / SPRD_EIC_PER_GROUP_NR);
+
+               shift = SPRD_EIC_BIT(offset);
+               value = readl_relaxed(base + reg) & SPRD_EIC_DATA_MASK;
+       }
+
+       return !!(value & BIT(shift));
+}
+
+static int sprd_eic_request(struct gpio_chip *chip, unsigned int offset)
+{
+       sprd_eic_update(chip, offset, SPRD_EIC_DBNC_DMSK, 1);
+       return 0;
+}
+
+static void sprd_eic_free(struct gpio_chip *chip, unsigned int offset)
+{
+       sprd_eic_update(chip, offset, SPRD_EIC_DBNC_DMSK, 0);
+}
+
+static int sprd_eic_get(struct gpio_chip *chip, unsigned int offset)
+{
+       return sprd_eic_read(chip, offset, SPRD_EIC_DBNC_DATA);
+}
+
+static int sprd_eic_direction_input(struct gpio_chip *chip, unsigned int 
offset)
+{
+       /* EICs are always input, nothing need to do here. */
+       return 0;
+}
+
+static void sprd_eic_set(struct gpio_chip *chip, unsigned int offset, int 
value)
+{
+       /* EICs are always input, nothing need to do here. */
+}
+
+static int sprd_eic_set_debounce(struct gpio_chip *chip, unsigned int offset,
+                                unsigned int debounce)
+{
+       struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
+       u32 shift, reg, value;
+
+       if (sprd_eic->type == SPRD_EIC_PMIC_DEBOUNCE) {
+               int ret;
+
+               shift = SPRD_PMIC_EIC_BIT(offset);
+               reg = SPRD_EIC_DBNC_CTRL0 + shift * 0x4;
+               ret = regmap_read(sprd_eic->map, sprd_eic->map_base + reg,
+                                 &value);
+               if (ret)
+                       return ret;
+
+               value &= ~SPRD_EIC_DBNC_MASK;
+               value |= debounce / 1000;
+               ret = regmap_write(sprd_eic->map, sprd_eic->map_base + reg,
+                                  value);
+               if (ret)
+                       return ret;
+       } else {
+               void __iomem *base = sprd_eic_group_base(sprd_eic,
+                                               offset / SPRD_EIC_PER_GROUP_NR);
+
+               shift = SPRD_EIC_BIT(offset);
+               reg = SPRD_EIC_DBNC_CTRL0 + shift * 0x4;
+               value = readl_relaxed(base + reg) & ~SPRD_EIC_DBNC_MASK;
+
+               value |= debounce / 1000;
+               writel_relaxed(value, base + reg);
+       }
+
+       return 0;
+}
+
+static int sprd_eic_set_config(struct gpio_chip *chip, unsigned int offset,
+                              unsigned long config)
+{
+       unsigned long param = pinconf_to_config_param(config);
+       u32 arg = pinconf_to_config_argument(config);
+
+       if (param == PIN_CONFIG_INPUT_DEBOUNCE)
+               return sprd_eic_set_debounce(chip, offset, arg);
+
+       return -ENOTSUPP;
+}
+
+static void sprd_eic_irq_mask(struct irq_data *data)
+{
+       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+       struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
+       u32 offset = irqd_to_hwirq(data);
+
+       switch (sprd_eic->type) {
+       case SPRD_EIC_PMIC_DEBOUNCE:
+               sprd_eic->reg[SPRD_EIC_DBNC_IE] = 0;
+               sprd_eic->reg[SPRD_EIC_DBNC_TRIG] = 0;
+               break;
+       case SPRD_EIC_DEBOUNCE:
+               sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IE, 0);
+               sprd_eic_update(chip, offset, SPRD_EIC_DBNC_TRIG, 0);
+               break;
+       case SPRD_EIC_LATCH:
+               sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTEN, 0);
+               break;
+       case SPRD_EIC_ASYNC:
+               sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTIE, 0);
+               break;
+       case SPRD_EIC_SYNC:
+               sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTIE, 0);
+               break;
+       default:
+               dev_err(chip->parent, "Unsupported EIC type.\n");
+       }
+}
+
+static void sprd_eic_irq_unmask(struct irq_data *data)
+{
+       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+       struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
+       u32 offset = irqd_to_hwirq(data);
+
+       switch (sprd_eic->type) {
+       case SPRD_EIC_PMIC_DEBOUNCE:
+               sprd_eic->reg[SPRD_EIC_DBNC_IE] = 1;
+               sprd_eic->reg[SPRD_EIC_DBNC_TRIG] = 1;
+               break;
+       case SPRD_EIC_DEBOUNCE:
+               sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IE, 1);
+               sprd_eic_update(chip, offset, SPRD_EIC_DBNC_TRIG, 1);
+               break;
+       case SPRD_EIC_LATCH:
+               sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTEN, 1);
+               break;
+       case SPRD_EIC_ASYNC:
+               sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTIE, 1);
+               break;
+       case SPRD_EIC_SYNC:
+               sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTIE, 1);
+               break;
+       default:
+               dev_err(chip->parent, "Unsupported EIC type.\n");
+       }
+}
+
+static void sprd_eic_irq_ack(struct irq_data *data)
+{
+       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+       struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
+       u32 offset = irqd_to_hwirq(data);
+
+       switch (sprd_eic->type) {
+       case SPRD_EIC_PMIC_DEBOUNCE:
+               break;
+       case SPRD_EIC_DEBOUNCE:
+               sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IC, 1);
+               break;
+       case SPRD_EIC_LATCH:
+               sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTCLR, 1);
+               break;
+       case SPRD_EIC_ASYNC:
+               sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTCLR, 1);
+               break;
+       case SPRD_EIC_SYNC:
+               sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTCLR, 1);
+               break;
+       default:
+               dev_err(chip->parent, "Unsupported EIC type.\n");
+       }
+}
+
+static int sprd_eic_irq_set_type(struct irq_data *data,
+                                unsigned int flow_type)
+{
+       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+       struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
+       u32 offset = irqd_to_hwirq(data);
+
+       switch (sprd_eic->type) {
+       case SPRD_EIC_PMIC_DEBOUNCE:
+               switch (flow_type) {
+               case IRQ_TYPE_LEVEL_HIGH:
+                       sprd_eic->reg[SPRD_EIC_DBNC_IEV] = 1;
+                       break;
+               case IRQ_TYPE_LEVEL_LOW:
+                       sprd_eic->reg[SPRD_EIC_DBNC_IEV] = 0;
+                       break;
+               default:
+                       return -ENOTSUPP;
+               }
+
+               irq_set_handler_locked(data, handle_level_irq);
+               break;
+       case SPRD_EIC_DEBOUNCE:
+               switch (flow_type) {
+               case IRQ_TYPE_LEVEL_HIGH:
+                       sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 1);
+                       break;
+               case IRQ_TYPE_LEVEL_LOW:
+                       sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV, 0);
+                       break;
+               default:
+                       return -ENOTSUPP;
+               }
+
+               irq_set_handler_locked(data, handle_level_irq);
+               break;
+       case SPRD_EIC_LATCH:
+               switch (flow_type) {
+               case IRQ_TYPE_LEVEL_HIGH:
+                       sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 0);
+                       break;
+               case IRQ_TYPE_LEVEL_LOW:
+                       sprd_eic_update(chip, offset, SPRD_EIC_LATCH_INTPOL, 1);
+                       break;
+               default:
+                       return -ENOTSUPP;
+               }
+
+               irq_set_handler_locked(data, handle_level_irq);
+               break;
+       case SPRD_EIC_ASYNC:
+               switch (flow_type) {
+               case IRQ_TYPE_EDGE_RISING:
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 
0);
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 
0);
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 1);
+                       irq_set_handler_locked(data, handle_edge_irq);
+                       break;
+               case IRQ_TYPE_EDGE_FALLING:
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 
0);
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 
0);
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 0);
+                       irq_set_handler_locked(data, handle_edge_irq);
+                       break;
+               case IRQ_TYPE_EDGE_BOTH:
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 
1);
+                       irq_set_handler_locked(data, handle_edge_irq);
+                       break;
+               case IRQ_TYPE_LEVEL_HIGH:
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 
0);
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 
1);
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 1);
+                       irq_set_handler_locked(data, handle_level_irq);
+                       break;
+               case IRQ_TYPE_LEVEL_LOW:
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTBOTH, 
0);
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTMODE, 
1);
+                       sprd_eic_update(chip, offset, SPRD_EIC_ASYNC_INTPOL, 0);
+                       irq_set_handler_locked(data, handle_level_irq);
+                       break;
+               default:
+                       return -ENOTSUPP;
+               }
+               break;
+       case SPRD_EIC_SYNC:
+               switch (flow_type) {
+               case IRQ_TYPE_EDGE_RISING:
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 1);
+                       irq_set_handler_locked(data, handle_edge_irq);
+                       break;
+               case IRQ_TYPE_EDGE_FALLING:
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 0);
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 0);
+                       irq_set_handler_locked(data, handle_edge_irq);
+                       break;
+               case IRQ_TYPE_EDGE_BOTH:
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 1);
+                       irq_set_handler_locked(data, handle_edge_irq);
+                       break;
+               case IRQ_TYPE_LEVEL_HIGH:
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 1);
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 1);
+                       irq_set_handler_locked(data, handle_level_irq);
+                       break;
+               case IRQ_TYPE_LEVEL_LOW:
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTBOTH, 0);
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTMODE, 1);
+                       sprd_eic_update(chip, offset, SPRD_EIC_SYNC_INTPOL, 0);
+                       irq_set_handler_locked(data, handle_level_irq);
+                       break;
+               default:
+                       return -ENOTSUPP;
+               }
+       default:
+               dev_err(chip->parent, "Unsupported EIC type.\n");
+               return -ENOTSUPP;
+       }
+
+       return 0;
+}
+
+static void sprd_eic_bus_lock(struct irq_data *data)
+{
+       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+       struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
+
+       mutex_lock(&sprd_eic->buslock);
+}
+
+static void sprd_eic_bus_sync_unlock(struct irq_data *data)
+{
+       struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+       struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
+       u32 offset = irqd_to_hwirq(data);
+
+       /* Set irq type */
+       sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IEV,
+                       sprd_eic->reg[SPRD_EIC_DBNC_IEV]);
+       /* Set irq unmask */
+       sprd_eic_update(chip, offset, SPRD_EIC_DBNC_IE,
+                       sprd_eic->reg[SPRD_EIC_DBNC_IE]);
+       /* Generate trigger start pulse for debounce EIC */
+       sprd_eic_update(chip, offset, SPRD_EIC_DBNC_TRIG,
+                       sprd_eic->reg[SPRD_EIC_DBNC_TRIG]);
+
+       mutex_unlock(&sprd_eic->buslock);
+}
+
+static int sprd_eic_match_chip_by_type(struct gpio_chip *chip, void *data)
+{
+       enum sprd_eic_type type = *(enum sprd_eic_type *)data;
+
+       return !strcmp(chip->label, sprd_eic_label_name[type]);
+}
+
+static void sprd_eic_handle_one_type(struct gpio_chip *chip)
+{
+       struct sprd_eic *sprd_eic = gpiochip_get_data(chip);
+       u32 group, n, girq;
+
+       for (group = 0; group * SPRD_EIC_PER_GROUP_NR < chip->ngpio; group++) {
+               void __iomem *base = sprd_eic_group_base(sprd_eic, group);
+               unsigned long reg;
+
+               switch (sprd_eic->type) {
+               case SPRD_EIC_DEBOUNCE:
+                       reg = readl_relaxed(base + SPRD_EIC_DBNC_MIS) &
+                               SPRD_EIC_DATA_MASK;
+                       break;
+               case SPRD_EIC_LATCH:
+                       reg = readl_relaxed(base + SPRD_EIC_LATCH_INTMSK) &
+                               SPRD_EIC_DATA_MASK;
+                       break;
+               case SPRD_EIC_ASYNC:
+                       reg = readl_relaxed(base + SPRD_EIC_ASYNC_INTMSK) &
+                               SPRD_EIC_DATA_MASK;
+                       break;
+               case SPRD_EIC_SYNC:
+                       reg = readl_relaxed(base + SPRD_EIC_SYNC_INTMSK) &
+                               SPRD_EIC_DATA_MASK;
+                       break;
+               default:
+                       dev_err(chip->parent, "Unsupported EIC type.\n");
+                       return;
+               }
+
+               for_each_set_bit(n, &reg, SPRD_EIC_PER_GROUP_NR) {
+                       girq = irq_find_mapping(chip->irq.domain,
+                                       group * SPRD_EIC_PER_GROUP_NR + n);
+
+                       generic_handle_irq(girq);
+               }
+       }
+}
+
+static void sprd_eic_irq_handler(struct irq_desc *desc)
+{
+       struct irq_chip *ic = irq_desc_get_chip(desc);
+       struct gpio_chip *chip;
+       enum sprd_eic_type type;
+
+       chained_irq_enter(ic, desc);
+
+       /*
+        * Since the digital-chip EIC 4 sub-modules (debounce, latch, async and
+        * sync) share one same interrupt line, we should iterate each EIC
+        * module to check if there are EIC interrupts were triggered.
+        */
+       for (type = SPRD_EIC_DEBOUNCE; type < SPRD_EIC_PMIC_DEBOUNCE; type++) {
+               chip = gpiochip_find(&type, sprd_eic_match_chip_by_type);
+               if (!chip)
+                       continue;
+
+               sprd_eic_handle_one_type(chip);
+       }
+
+       chained_irq_exit(ic, desc);
+}
+
+static irqreturn_t sprd_pmic_eic_irq_handler(int irq, void *data)
+{
+       struct sprd_eic *sprd_eic = data;
+       struct gpio_chip *chip = &sprd_eic->chip;
+       u32 n, girq, val;
+       int ret;
+
+       ret = regmap_read(sprd_eic->map, sprd_eic->map_base + SPRD_EIC_DBNC_MIS,
+                         &val);
+       if (ret)
+               return IRQ_RETVAL(ret);
+
+       val &= SPRD_PMIC_EIC_DATA_MASK;
+
+       for (n = 0; n < chip->ngpio; n++) {
+               if (!(BIT(n) & val))
+                       continue;
+
+               sprd_eic_update(chip, n, SPRD_EIC_DBNC_IC, 1);
+
+               girq = irq_find_mapping(chip->irq.domain, n);
+               handle_nested_irq(girq);
+       }
+
+       return IRQ_HANDLED;
+}
+
+static int sprd_eic_probe(struct platform_device *pdev)
+{
+       const struct sprd_eic_data *pdata;
+       struct gpio_irq_chip *irq;
+       struct sprd_eic *sprd_eic;
+       struct resource *res;
+       int ret, i;
+
+       pdata = of_device_get_match_data(&pdev->dev);
+       if (!pdata) {
+               dev_err(&pdev->dev, "No matching driver data found.\n");
+               return -EINVAL;
+       }
+
+       sprd_eic = devm_kzalloc(&pdev->dev, sizeof(*sprd_eic), GFP_KERNEL);
+       if (!sprd_eic)
+               return -ENOMEM;
+
+       mutex_init(&sprd_eic->buslock);
+       spin_lock_init(&sprd_eic->lock);
+       sprd_eic->type = pdata->type;
+
+       sprd_eic->irq = platform_get_irq(pdev, 0);
+       if (sprd_eic->irq < 0) {
+               dev_err(&pdev->dev, "Failed to get EIC interrupt.\n");
+               return sprd_eic->irq;
+       }
+
+       if (sprd_eic->type == SPRD_EIC_PMIC_DEBOUNCE) {
+               sprd_eic->map = dev_get_regmap(pdev->dev.parent, NULL);
+               if (!sprd_eic->map)
+                       return -ENODEV;
+
+               ret = of_property_read_u32(pdev->dev.of_node, "reg",
+                                          &sprd_eic->map_base);
+               if (ret) {
+                       dev_err(&pdev->dev, "Failed to get EIC base address\n");
+                       return ret;
+               }
+
+               ret = devm_request_threaded_irq(&pdev->dev, sprd_eic->irq, NULL,
+                                               sprd_pmic_eic_irq_handler,
+                                               IRQF_TRIGGER_LOW |
+                                               IRQF_ONESHOT | IRQF_NO_SUSPEND,
+                                               dev_name(&pdev->dev), sprd_eic);
+               if (ret) {
+                       dev_err(&pdev->dev, "Failed to request EIC IRQ.\n");
+                       return ret;
+               }
+       } else {
+               for (i = 0; i < SPRD_EIC_MAX_GROUP; i++) {
+                       /*
+                        * We can have maximum 3 groups EICs, and each EIC has
+                        * its own base address. But some platform maybe only
+                        * have one group EIC, thus base[1] and base[2] can be
+                        * optional.
+                        */
+                       res = platform_get_resource(pdev, IORESOURCE_MEM, i);
+                       if (!res)
+                               continue;
+
+                       sprd_eic->base[i] = devm_ioremap_resource(&pdev->dev,
+                                                                 res);
+                       if (IS_ERR(sprd_eic->base[i]))
+                               return PTR_ERR(sprd_eic->base[i]);
+               }
+       }
+
+       sprd_eic->chip.label = sprd_eic_label_name[sprd_eic->type];
+       sprd_eic->chip.ngpio = pdata->num_eics;
+       sprd_eic->chip.base = -1;
+       sprd_eic->chip.parent = &pdev->dev;
+       sprd_eic->chip.of_node = pdev->dev.of_node;
+       sprd_eic->chip.direction_input = sprd_eic_direction_input;
+       switch (sprd_eic->type) {
+       case SPRD_EIC_PMIC_DEBOUNCE:
+               /* fall-through */
+       case SPRD_EIC_DEBOUNCE:
+               sprd_eic->chip.request = sprd_eic_request;
+               sprd_eic->chip.free = sprd_eic_free;
+               sprd_eic->chip.set_config = sprd_eic_set_config;
+               sprd_eic->chip.set = sprd_eic_set;
+               /* fall-through */
+       case SPRD_EIC_ASYNC:
+               /* fall-through */
+       case SPRD_EIC_SYNC:
+               sprd_eic->chip.get = sprd_eic_get;
+               break;
+       case SPRD_EIC_LATCH:
+               /* fall-through */
+       default:
+               break;
+       }
+
+       sprd_eic->intc.name = dev_name(&pdev->dev);
+       sprd_eic->intc.irq_ack = sprd_eic_irq_ack;
+       sprd_eic->intc.irq_mask = sprd_eic_irq_mask;
+       sprd_eic->intc.irq_unmask = sprd_eic_irq_unmask;
+       sprd_eic->intc.irq_set_type = sprd_eic_irq_set_type;
+       sprd_eic->intc.flags = IRQCHIP_SKIP_SET_WAKE;
+
+       irq = &sprd_eic->chip.irq;
+       irq->chip = &sprd_eic->intc;
+       if (sprd_eic->type == SPRD_EIC_PMIC_DEBOUNCE) {
+               sprd_eic->intc.irq_bus_lock = sprd_eic_bus_lock;
+               sprd_eic->intc.irq_bus_sync_unlock = sprd_eic_bus_sync_unlock;
+               irq->threaded = true;
+       } else {
+               irq->handler = handle_simple_irq;
+               irq->default_type = IRQ_TYPE_NONE;
+               irq->parent_handler = sprd_eic_irq_handler;
+               irq->parent_handler_data = sprd_eic;
+               irq->num_parents = 1;
+               irq->parents = &sprd_eic->irq;
+       }
+
+       ret = devm_gpiochip_add_data(&pdev->dev, &sprd_eic->chip, sprd_eic);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "Could not register gpiochip %d.\n", ret);
+               return ret;
+       }
+
+       platform_set_drvdata(pdev, sprd_eic);
+       return 0;
+}
+
+static const struct of_device_id sprd_eic_of_match[] = {
+       { .compatible = "sprd,sc9860-eic-debounce", .data = 
&sc9860_eic_dbnc_data },
+       { .compatible = "sprd,sc9860-eic-latch", .data = &sc9860_eic_latch_data 
},
+       { .compatible = "sprd,sc9860-eic-async", .data = &sc9860_eic_async_data 
},
+       { .compatible = "sprd,sc9860-eic-sync", .data = &sc9860_eic_sync_data },
+       { .compatible = "sprd,sc27xx-eic-debounce", .data = &pmic_eic_dbnc_data 
},
+       { /* end of list */ },
+};
+MODULE_DEVICE_TABLE(of, sprd_eic_of_match);
+
+static struct platform_driver sprd_eic_driver = {
+       .probe = sprd_eic_probe,
+       .driver = {
+               .name = "sprd-eic",
+               .of_match_table = sprd_eic_of_match,
+       },
+};
+
+module_platform_driver(sprd_eic_driver);
+
+MODULE_DESCRIPTION("Spreadtrum EIC driver");
+MODULE_LICENSE("GPL v2");
-- 
1.7.9.5

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